Why do you NEED to have an ADSL filter?

Please excuse my ignorance, and I need a really simple explanation; We have a standard ADSL filter, and our phone line is really noisy, with lots of hiss. When I spoke to Telecom about this, they asked me to take the filter off, and the line was crystal clear. They said that my filter was probably old, and I should buy a new one. I did. That has made no difference at all. Now they have called today and offered an ADSL2 Wireless Modem as our local exchange has "had an upgrade". Is this going to make any change to the phone line at all? Or just increase performance on our computer. I would appreciate some advice please, good people!

geek_mazzy1, May 19, 6:14 pm

I shouldn't think that it would make any change to your phone line.

Have you tried another filter? You need one for any device *apart from* an adsl modem using a phone jack.

geek_dunedin_ree, May 19, 6:18 pm

Yep - tried another new filter, and that made no discernable difference. Very annoying!

geek_mazzy1, May 19, 6:21 pm

If it is a free one, then take their offer by all means.
Chances are that you have still got a Telephone device plugged into a phonejack without a filter inline. this can also cause moise like you describe. Most people forget that often the Sky decoder is plugged into the line as well and forget to add a filter for it.
Have a good look around for another phone/fax/modem/answer machine etc. . plugged in without a filter.

geek_pheonix, May 19, 6:24 pm

You're doing something wrong. Check the phone is going into the phone plug on the filter. try turning the modem off to see if the noise is still there, if it is, the line itself is crud.

geek_jcmp21, May 19, 6:29 pm

It's in my business, and the only extra thing we have is an Eftpos machine. The phone is definitely going into the phone plug on the filter, but when I get in tomorrow I will try turning the modem off and see what happens.

geek_mazzy1, May 19, 6:31 pm

Rather than turn it off , unplug the device from the phoneline and see if the noise disappears. Just turning it off may not affect the noise as there would be components still across the line.
If the EFTPOS is plugged into the phoneline , then it may also cause a problem.
The easiest way is just uplug everything (except the modem and filter) and see if the noise is still there, then plug each thing in till you get the noise again.

geek_pheonix, May 19, 6:36 pm

Does the eftpos machine have a filter too? Everything that is using the phone line needs to be connected to one.

geek_psx_man, May 19, 7:08 pm

take anything that's free, but if you remove a filter and things "go right" then i'd guess there is something wrong with the way your phone/ adsl is configured.

geek_jamjars05, May 19, 7:15 pm

Great advice all round, thank you. I will do some experimentation when I go in tomorrow. Sadly, jamjars05, there is no such thing as a free lunch, and I have to sell my soul for 2 years more with Telecom broadband... ... .

geek_mazzy1, May 19, 7:18 pm

mazzy1, has any work or changes been done on your phone line recently? has the noise always been there, or has it just started recently? My back ground is, I used to work in the telecomunication industry [ex telecom faultman].

geek_dishd, May 19, 7:38 pm

No dishd - it has always been a partcularly crappy line. I have been reluctant to call Telecom because they will charge me an arm, leg and possibly spleen to check it out. I put it down to "just one of those things", but it is really, REALLY annoying me!

geek_mazzy1, May 20, 9:13 am

mazzy1, you are so cheap, ... business must suck if you have to come here for free help, . . you do realize that getting a tech in is a business expense? , ...

geek_kevin16, May 20, 9:20 am

You only get charged if the fault is inside the customer premises AND if you don't have the wiring maintenance charge on your invoice. Otherwise it's their cost to fix a noisy line, you've already paid for this service as part of your fee to your ISP who has wholesaled the line from Chorus.

My observation is that the Chorus technician will always try and say that the fault is in the customer premises, that you don't have a wiring maintenance contract, and that you WILL have to pay. I've seen this from more than 1 Chorus technician, therefore I suggest it is part of their business practice.

The last time it happened, two Chorus technician's knocked at the door and I asked "What have you fixed so far external to the premises? " - and the answer was "Nothing. As we told you yesterday, the fault is in your customer premises wiring and you will have to pay to have it fixed". Then I let them in, and showed them the new demarcation socket attached directly to their inch of copper coming through the concrete block wall - and of course the fault had miraculously cleared, despite them not having done anything external to the premises.

So my tip: attach a new phone jack with an "approved by Telecom" sticker directly to the copper wire at the point of entry to the premises (ie; a demarcation point) so that you can test the service without having any of the customer premises wiring attached.

geek_gyrogearloose, May 20, 9:32 am

Hey - thanks awfully for your input. I might be 'cheap' but at least I can read, so suggest you check out my original question. Are you suggesting that free help should only be relevant for some people and not others? If you have nothing to contribute then I suggest you skulk off somewhere else - perhaps try Crafts and Hobbies?

geek_mazzy1, May 20, 9:50 am

whatever, you could chase your tail for a long time, a tech will find the issue and fix it in less time than this thread has been in exsistance, guess it comes down to f its a 'real issue' or not eh! ?

geek_kevin16, May 20, 10:00 am

You could be quite right. However I just want to cover all my bases and try some solutions before I call in the experts. And if I can learn something new along the way - then that's a bonus, I think. No harm in that, is there?

geek_mazzy1, May 20, 10:26 am

Oh - and business is just fine, thanks very much!

geek_mazzy1, May 20, 10:27 am

mazzy1 do you know if the hissing noise is only present when the modem is plugged in and synced-up, or is the hissing noise there regardless of modem plugged in or not?

geek_dishd, May 20, 8:13 pm

My filter died and i got no incoming telephone calls.

geek_axelvonduisberg, May 21, 5:49 pm

how long did it take to work that out? , and I must say, ... your account looks exceedingly young for its age, . . how do you keep it looking so good?

geek_kevin16, May 21, 6:00 pm

Is it a cordless phone or phone/fax machine by any chance? Also, if the eftpos is on the same line, it should have a filter as well. Possibly you need to "Hardwire Split" the ADSL. This is far more successful where Eftpos, Alarms, Faxes, Cordless Phones etc are used.

geek_d.snell, May 21, 6:10 pm


I had a noisy phone line a while back and had a succession of Chorus Techs around to check my line over and over again. One technician went beyond the call of duty and replaced my in-line filter (which made no difference and mine was put back).

The long and the short of it was that it was one dirty fuse connection at the exchange. Get the technician to go to your exchange and simply pull and replace the fuses. Amazing what a little dirt and bad contact will do!

geek_sighkick, May 21, 7:09 pm